noun
safety valve
A mechanical device that automatically releases pressure from a boiler, pressure vessel, or piping system to prevent explosion. Also used figuratively for an outlet that relieves stress or tension.
ボイラーには安全弁が取り付けられている。
A safety valve is installed on the boiler.
彼にとってカラオケはストレスの安全弁だ。
For him, karaoke is a safety valve for stress.